Clutch



May 15, 1945.

T- L- FAwlcK CLUTCH Filed May 2l. 1941 2 sheets-sheet 1 INVENTOIR l www.; Z, Fina/ck ATTORNEY May l5, 1945. T. FAwlcK CLUTCH 2 Shee-ts-Sheet 2 Y,

Filed May 21, 1941 K IN VEN TO'R.

Mmm l. fha/f ATTORNEY Patented May 15, 1945 UNITED STATES PATENT OFFICE Thomas L. Fawick, Akron, Ohio Application May 21, zeslogo. 394,528 j 14 Claims.

This invention relates to clutches and especially to centrifugal clutches, although not wholly limited thereto.

Its chief objects are to provide simplicity and inexpensiveness of construction; to provide facility of assembly, disassembly and repair; to provide for desirable cushioning of the torque; to provide desirable flexible coupling characteristics; to provide ready adjustability for adapting the clutch to engage and disengage at determinate speeds; to provide adjustability as to the cushioning of the torque; and to provide a self-energizing effect.

f the accompanying drawings:

Fig. l is a section, on line I-l of Fig. 2. of a centrifugal clutch embodying my invention in one of its preferred forms.

Fig. 2 is a section of the same on line 2-2 of Fig. 1.

Fig. 3 is a section. on line 3--3 of Fig. 4, of another clutch embodying my invention in another of its preferred forms.

Fig. 4 is a section on line 4-4 of Fig. 3.

Fig. 5 is a fragmentary section illustrating a modification of the clutch of Figs. 3 and'4.

Referring to the drawings, the clutch of Figs. 1 and 2 comprises a bell-shaped driven member l@ secured upon a driven shaft il having a straight key i2 and a clutch-hub I3 secured upon a driving shaft id having a straight key I5.

Secured upon the hub I3, as by cap-screws I6, i6, is a ring il formed with a circumferential series of bosses such as the boss I8, Fig. 2, each formed with an aperture in which is fitted the tapered head i3 of a stud bolt 20.

Mounted upon each of the stud bolts 2U; and adapted to be clamped in an axial direction between the adjacent face of the boss I8 and a clamping washer 22 mounted upon the stud bolt, by the setting up of a nut 23, are two frustoconical rubber bushings 2l, 24, mounted upon the stud bolts with their smaller ends abutting each other, and within a. complementally doubletapered hole formed in the hub of a centrifugal arm 25.

This construction is such that 'the rubber bushings 24, through which the torque is transmitted from the stud bolts to the centrifugal arms 23, can be put under radial compression by the setting up of the nuts 23 and thus pre-loaded, to such degree as may be desired, for modifying the torque-cushioning effect of the rubber bushings.

This construction also is such that the rubber bushings, completely insulating the centriugal arms 25 from the ring I1, provide substantial iiexible coupling effect in the clutch.

Each of the centrifugal arms 25 is formed with an arcuate outer face upon which is secured, as by rivets 26, 26, a wear shoe 21 adapted -frictionally to engage the cylindrical inner face,

I0, of the bell-shaped driven member I0, when the centrifugal arm is swung outward, about its stud bolt 20 as an axis, by rotation of the driving assembly, the deformability of the rubber bushings 24 permitting such swinging movement with only moderate resistance although the construction is such that the rubber bushings are capable of transmitting heavy torque, with only'a desirable amount of cushioning of the torque, and with variation of their torque--cushioning effect, and of their resistance to outward movement of the arms 25, in accordance with the setting up of the nuts 23.

As the swing axes of the arms 25 are substantially closer to the axis of rotation than are the frictional engagement surfaces of the wear shoes` there is a substantial self-energizing effect when the direction of drive is counter-clockwise in -the assembly as viewed in Fig. 1, and because of the ment pressure is not made highly non-uniform by the self-energizing feature.

For further, and independently adjustable resistance to the outward swinging of the centrifugal arms 25, each of them has mounted in it near its outer end a stud bolt 28, extending toward the axis of rotation and provided with a springseat washer 29 and an adjusting nut 30, and a compression spring 3i is mounted between the spring-seat washer 29 and a spring seat 32 formed on and laterally projecting from the ring i1.

The embodiment shown in Figs. 3 and 4 comprises a bell-shaped driven member 28 secured upon a driven shaft 29 having a straight key 30 and a clutch-hub spider 3l secured upon a driving shaft 32 having a straight key 33.

A circumferential series of stud 'bolts 34, 34 having tapered heads are mounted in the arms of the spider-shaped clutch-hub 3| and each studbolt 34 is provided with a clamping washer 35 and a nut 36 for' clamping in an axial direction, against the adjacent face of the spider arm. a

rubber bushing member 31 and thereby putting it` under transverse compression between adjacent members of a circumferential series of centrifugal members 38, 33 provided with respective friction facings or wear shoes 39, 39.

Il'or the centrifugal members l. in alignment each is formed at each of its ends with amedial flange Il tting in a circumferential groove 4I (Fig. 4) formed in the rubber bushing.

The rubber bushings are sufiiciently deformable to permit the small-amplitude outward movement of the members 3l, under centrifugal force. for engagement of the clutch, and yet they are adapted to transmit. and provide desirable cushioning of. heavy torque. Their resilience is such as to provide for retraction of the members 3l for clutch disengagement at moderate speeds, but for higher speeds for engagement and disengagement the members 3l preferably are connected to the hub member 3| by respective pull springs I2. 42.

In this embodiment, as in the embodimen shown in Figs. 1 and 2, the effective modulus of the rubber bushings, for cushioning of torque vand for resistance to centrifugal force, can be varied by the setting up or backing on of the clamping nuts after the parts have been assembled.

self-energizingis present as to either direction of drive, because the engagement faces of the shoes in Figa-.3 and ifa' rubber member -ofinon cylindrical, inwardly tapered form is employed and is formed with interlocking-ribs Il, 44 occupying complemental grooves formed in the adjacent ends of the centrifugal members, il, 38', and the rubber member preferably is provided with vulcanized-on metal facingsl, 45, this construction opposing to the centrifugal force a less localized resistance of the rubber to deformation.

Each of the embodiments provides some or all of the advantages set out in the above statement 3. A centrifugal clutch comprising a driving structure and a driven structure and, vinterposed operatively between the two, a series of substantially rigid centrifugal members and a series of pre-loaded torque-transmitting bodies of resiliently deformable material, said bodies being adapted to yield under the centrifugal force of said rigid centrifugal members for clutch engagement and having their outer surfaces interlocked with themfor transmission of torque and for resisting, in compression. radially outward movey ment of the adjacent portions of said members,

In this embodiment shown in Figs. 3 and 4 andeach being mounted upon a central stud and being of approximately the same maximum radial depth in all planes that are axial with relation to the stud.

4. A centrifugal clutch comprising a driving structure and a driven structure and, interposed operatively between the two, a series of rigid centrifugal members and a series of pre-loaded torque-transmitting bodies of resiliently deformable material, said bodies being tapered in a direction parallel to the axis of rotation and preloaded by clamping pressure applied in that direction and Ibeing adapted to yield under the centrifugal force of said rigid centrifugal members for clutch engagement and having their outer faces interlocked with them for transmission of torque and yfor resisting, in compression, radially outward movement of the adjacent portions of said members.

5. A clutch comprising a clutch-hub, a circumferential sexies of frictional engagement members pivoted thereon, and torque-transmitting bodies of resiliently deformable material in- Isulating adjacent portions of said members from said hub, said bodies being adapted to yield for of objects, and other modications are possible within the scope of the appended claims.

I claim:

l. A centrifugal clutch comprising a driving hub, a circumferential series of substantially rigid centrifugal members and, interposed between said hub and said members, a series of torque-transmitting bodies of resiliently deformable material, said bodies being adapted to yield under the centrifugal force of said rigid centrifugal members for clutch engagement and having their outer surfaces interlocked with them for transmission of torque and for resisting, in compression, radially outward movement of the adjacent portions of said members.

2. A centrifugal clutch comprising a driving hub, a circumferential series of substantially rigid centrifugal members and, interposed between said hub and said members, a series of pre-loaded torque-transmitting bodies of resiliently deformable material, said bodies being adapted to yield under the centrifugal force of said rigid centrifugal members for clutch engagement and having their outer surfaces interlocked with themv for transmission of torque and for resisting, in compression, radially outward movement Vof the adjacent portions of said members.

outward movement of said members for clutch engagement and having their outer faces interlocked withv said members for transmission of torque and for resisting, in compression, outward movement of the adjacent portions of said members.

6. A clutch comprising a clutch-hub, a circumferential series of frictional engagement members pivoted thereon and torque-transmitting bodies of resiliently deformable material insulating adjacent portions of said members from said hub and constituting their pivotal mountings, said bodies being adapted to yield for outward movement of said members for clutch engagement and having their outer faces interlocked with said members, for transmission of torque and for resisting, in compression, outward movement of the adjacent portions of said members.

7. A centrifugal clutch comprising a driving structure and a driven structure and, interposed operatively between the two, a series of centrifugal members and a series of torque-transmitting bodies of resiliently deformable material adapted to yield under the centrifugal force of said centrifugal members for clutch engagement and interlocked with said members for transmitting torque from one of said structure to the other, through the centrifugal members, by compressoin in the said bodies, the assembly including springs for resisting the centrifugal force of said centrifugal members.

8. A centrifugal clutch comprising a driving structure and a driven structure and, interposed operatively between the two, a series of centrifugal members and a series of torque-transmitting bodies of resiliently deformable material adapted to yield under the centrifugal force of said members for clutch engagement and interlocked with said members for transmitting torque from one of said structures to the other, through the centrifugal members, by compression in the lthe said bodies, the assembly including springsv studs projecting therefrom in a direction parallel with the axis of rotation, torque-transmitting bushings of resiliently deformable material mounted respectively on said studs, and friction mounted on said studs, and centrifugal members atl-engagement members mounted respectively in non-slipping relation upon said bushings, each oi said bushings being of approximately the same maximum radial depth in all planes that are axial with relation to the stud. and said frictional engagement members being adapted to shift, with relation to their respective studs, both radially and axially of the assembly but only by overcoming the yielding resistance oi the bushings.

10. A clutch comprising a. clutch-hub, a series allel with the ams of rotation, torque-transmitting bushings of resiliently deformable material mounted respectively' on said studs, vfrictional-ena pre-loaded condition as to the transmission of torque.' Y

11. A clutch comprising a clutch-hub, a series of studs projecting therefrom in a direction parallel with the axis of rotation, torque-transmitting bodies of lresiliently deformable material mounted on said studs, and centrifugal members each mounted upon two of the said bodies.

12. A clutch comprising a clutch-hub, a series of studs projecting therefrom in a-direction parallel with the axis of rotation, torque-transmitting bodies of resiliently deformable material l of studs projecting therefrom in a direction parf of studs-projecting therefrom in a direction pargagement members mounted respectively uponVA said bushings, said bushings being adapted' to yield for outward movement of said members for clutch engagement and having 'their outer faces interlocked with said members for on of torque and for resisting, n compression, outward movement of adjacent portions oi' said members, and means clamping said bushings in an 35 tosaid nroiections. axial direction and thereby maintaining them in 'g allei with the axis of rotation, torque-transmit' ioning material mounted on each of said stud members and formed with interlocking projec- Y tions, frictional engagement members interlocked with said projections, and a metal facing adhered moms L. Fawrcm 

